Because of their complexity, integrated circuits, such as systems on a chip (SOCs), are typically designed using automated design tools, such as a computer-aided design (CAD) system. The CAD system can include automated processes to implement, verify, and improve performance, reliability, and manufacturability of the device design. For example, to verify reliability of the device design, the CAD system simulates the behavior of the device based on input stimuli and determines whether physical attributes of the device conform to design rule specifications.
In certain instances it can be desirable for devices of a same type to exhibit performance characteristics that are closely matched. Traditionally this has been accomplished by ensuring that the placement and routing of such devices themselves are the same, thus improving the performance similarity of the signal processing performed by each of the matched devices. For example, sense amplifiers, differential pairs, operational amplifiers, current mirrors, and other circuits can be designed to have similar electrical performance characteristics to other devices of the same type by matching their placement and routing to each other. However, even when the mask layer shapes that make up the devices are the same and the matched devices are both compliant with a common set of design rules, the devices may operate sufficiently differently from each other to cause unacceptable mismatches in the electrical performance of the devices for an intended application. Accordingly, there is a need for techniques to determine whether the extent of mismatch in circuits or devices that are expected to perform similarly to each other is acceptable.